Refrigeration apparatus



Nov. 24, 1942. R. E. TOBEY REFRIGERATION APPARATUS 3 Sheets-Sheet 1Filed July 25, 1940 INVENTOR RAYMOND E.Toaz-/,

ATTOR Y Nov. 24, 1942. R. 5. TOBEY REFRIGERATION APPARATUS Filed July25, 1940 s Sheets-Sheet 2 f INVENTOR RAYMOND E- v W lTNESSE S:

5 H Qg iz TOBEY ATI'ORN N -24,1 42 R. E. TOE-Ev "2,303,18

REFRIGERATION APPARATUS Filed Jul 25, 1940 s Shegts-Sheotfi wnuasszs: QiNVENTOR RAYMOND E .TOBEY Patented Nov. 24, 1942 UNITED STATES 'PATJENTIOFFICE a oms: 7 I v p Raymond E. Tobey, Springfield,

to Westinghouse Electric &

Mass, assign."

Manufacturing ompany, East Pittsburgh, Pa... a corporation 7Pennsylvania Application July 25, 1940, Serial No. 347,398

9 Claims.

This invention relates to refrigeration api the temperatures of both thecooling unit and the media ambient the refrigerator.

A further object is to provide a compensated Rcontrol of the typedescribed which does not seriously affect the ice freezing capacity ofthe refrigeration apparatus it is controlling in low room temperatures.

These and other objectsare effected by my invention as will be apparentfrom the following description and claims taken in connection with theaccompanying drawings, forming a part of this application, in which:

Fig. 1 is a schematic drawing of the control apparatus of this inventionapplied to a refrigerator;

Fig. 2 is 'a detailed view showing the position of the elements of thecontrol apparatus when the temperature of the media ambient therefrigerator is low; Fig. 3 is a view showing the position of theelements of the control apparatus when the temperature of the mediaambient the refrigerator is high;

Fig. 4 illustrates a modification of the control apparatus of thisinvention applied to a refrigerator;

Fig. 5 is a detailed view of the modification shown in Fig. 4, showingthe positions of the elements of the control apparatus when thetemperature of the media ambient the refrigerator is low:

Fig. 6 is a detailed view of the modification shown in Fig; 4 showingthe position of the elements of the control apparatus when thetemperature of the mediaambient the refrigerator is high;

Fig. 7 is a schematic drawing of another modification of the invention;1 I Fig. 8 is a detailed view showing the position I of the elements ofthe control apparatus when perature of' the media ambient therefrigerator I is high.

Referring specifically to the drawings for a detailed description oftheinvention, reference numeral 8 designates a cabinet of a refrigeratorhaving insulated walls 9 forming a food storage compartment Ill with anevaporator or cooling unit ll therein.- The evaporator H is suppliedwith liquid refrigerant through a capillary tube l2 which receives itssupply from a condenser [3 into which compressed refrigerant is pumpedthrough a conduit M by a compressor IS. The compressor i5 withdraws thevaporized refrigsnap-acting switch 2! placed in one of the lines erantfrom the evaporator ll through a conduit IS. The compressor i5 is drivenby means of an electric motor l1 which receives electrical energy fromlines l8. The condenserv l3 and the compressor I5 are cooled by a fan 20which circulates air through thecondenser l3 and over the compressor I5.

A thermostatic device l9 controls the current supply to the electricmotor ll by 'means of a I8. The switch 2| comprises a fixed contact 22and a movable contact 23 carried on an arm 24 which is actuated by anovercenter linkage comprising a lever 25 and a spring 26. The lever 25is actuated by a. Sylphon bellows 21, which in turn is actuated bythevapor pressure of a vola- .tile liquid 28 in a vessel 29 (see Figs. 2and 3) adjacent the evaporator H. v A tube 30 connects the Sylphonbellows 2] with the vessel 29. The vapor pressure of the volatile liquid28 at which the snap-acting switch 2! is actuated may be varied'byturning a threaded shaft ll which adjusts the pressure of a spring 35 onthe lever 25.

Vessel 29 is an L'-shaped tube with the shorter leg 39 lying in contactwith the cooling unit ll and the longer leg- 4| extending away from thecooling unit ll into the relatively warmer food storage chamber III. Thevessel 29 accordingly the temperature of the media ambient the refrigivessel 29, however, varyin response to varies in temperature, the colderportion beingthe portion 39 in contact with the cooling unit I l,

and the warmer portion being the portion. ll,- which portion varies intemperature and is progressively warmer depending on the distance of thevarious elements thereof from the cooling unit I l. The temperatures ofall portions of the the temperature of the cooling unit ll. v

In accordance with the invention, a chamber 32 is located in the ambientair of the refrigerator. The chamber 32 is divided by an-elasticdiaphragm 33, such as rubber, into two compart- "'ments 34 and 38. Thecompartment 38 com-.

' and 38, the bellows 21, the tube 38, and the vessel 28 is exhaustedprior to the introduction of .the liquids so that the only pressures inthe chambers are the pressures of the vapors of the respective liquids.

The liquids 28 and 38 are of such a nature that when the food storagecompartment I8 is refrigerated, the vapor pressure of the liquid 38exceeds that of the liquid 28 when the temperature of the air ambientthe refrigerator is high and is below that of the liquid 28 when thetemperature of the air ambient the refrigerator is low. Suitable liquidsfor this purpose are methyl chloride in the vessel 28 and methyl bromidein the compartment. Assuming a temperature of the cooling unit II suchthat the warmest portion of the methyl chloride is F., the vaporpressure of the methyl chloride'would be 13.8 pounds per square inch.The vapor pressure of the methyl bromide in a 60 F. room would be 8.7pounds perature of the liquid line 48 as compared to the diiferencebetween the temperature of cabinet air and the "cut-on temperature ofthe liquid line 48.

The control is preferably so proportioned that it decreases. thetemperature of the cooling unit II, just sufliciently to offset theadditional heat leakage through the refrigerator walls when thetemperature of the ambient air rises. This maintains the averagetemperature of the air in the refrigerator substantially constant. Thecontrol -may also be adapted for over-compensation so that therefrigerator temperature drops when the temperature of the ambient airincreases. This may be effected by lengthening the vessel 28 anddecreasing its diameter.

per square inch and in a 90 F. room would be 26.7 pounds per squareinch. The pressure of the methyl bromide is less, therefore, than thatof the methyl chlqride in a cold room and greater than that of themethyl chloride in a hot room so that when the temperature of theambient air is low, the position of the diaphragm 33 will be towards theright as indicated in Fig. 2, and when the temperature of the ambientair is high,

the diaphragm 33 will be moved to the left as shown in Fig. 3.

The'movement of the diaphragm 33 to the left forces the vapor of' theliquid 28 from the compartment 38, and the increased pressure causes thevapor to condense in the vessel 28. An increase in the quantity of theliquid 28 in the vessel 28 moves the dividing line 48 between the liquid28 and its vapor farther away from the cooling unit. Thedividing line 48will hereafter "be referred to as the liquid line 48 of the liquid Whenthe temperature of the air ambient the refrigerator is low, the liquidline 48 is close to the cooling unit II as shown in Fig. 2 and closelyfollows the temperature thereof. Under these circumstances the volatilefluid 28 closes the switch 2| when the temperature of the cooling unitII rises to the cut-on temperature and opens the switch when thetemperature of the cooling unit II drops to the cut-off temperature.However, when the temperature of the air ambient the refrigerator ishigh, the liquid line 48 of the volatile fluid 28 is moved away. fromthe cooling unit I I as shown in Fig. 3. The temperature of the coolingunit I I must now be much lower than formerly to cool the liquid at theliquid line 48 to the cut-oil temperature and similarly the liquid atthe liquid line 48 reaches the cut-off" temperature only after thecooling unit II has been cooled to considerably below this temperature.It will be apparent from the above that the temperature of the coolingunit I I varies with the temperature of the ambient air and is decreasedin temperature when. the temperature ambient the refrigerator increasesand vice versa. The decrease in the cut-off temperature will also befound to be greater than the decrease in the cut-on temperature due tothe greater temperature difference between the temperature of the air inthe cabinet and the cut-off tem- 'Applicants device provides for thefreezing of ice cubes andthe like by extending the portion 38 of thevessel 28 along the cooling unit. It will be apparent that even thoughthe liquid line 48 drops below the level indicated in Fig. 2 in a verylow ambient temperature,the temperature of the liquid at the liquidlevel 48 will not change relative to that of the cooling unit I I, andthe switch will be opened and closed at substantially the sametemperatures as for the conditions indicated in Fig. 2, at which afreezing temperature is maintained within the cooling unit I I.

The modification shown in Figs. 4, 5, and 6 produces a similar result asthe modifications previously described and like parts are provided withthe same reference numerals. In this modiflcation a receptacle 58connects through a tube 5| with the tube 38. The receptacle 58 islocated in the air ambient the refrigerator and contains a mineral oil52 or other vapor-absorbing material. The volatile fluidin the vessel 28of this modification comprises a fluid such as dichlorodifluoromethane53 which is soluble in the mineral oil 52 inversely proportional to thetemperature of the oil 52.

When the temperature of the ambient air is cool, a quantity of thedichlorodifiuoromethane vapor is absorbed by the mineral oil 52 and someof the dichlorodifluoromethaneliquid 53 in the vesesl 28 vaporizes toreplace the absorbed vapor. The vaporization of thedichlorodifiuoromethane liquid 53 causes the liquid line 48 thereof tomove closer to the evaporator II. When the temperature of the airambient the refrigerator is high, a certain portion of the vaporabsorbed by the mineral oil 52 is driven 011 and this vapor con--denses'in the portion H of the vessel 28 in the same manner as in thefirst-described modification. The compensating action of thedichlorodifluoromethane liquid 53 at the liquid line 48 is the same asthe volatile liquid 28 in the vessel 28 described in the firstmodification of the invention;

In the modification shown in Figs. 7, 8, and 9. somewhat similarapparatus is utilized as in the previous modification and like parts areprovided with the same reference numerals. The liquid line 48 in thismodification is moved back and forth by the expansion and contraction ofa fluid, preferably a liquid 58, which is contained in a receptacle 58secured to the metal of the outer shell 52 of the refrigerator. Thereceptacle 58 connects to the lower portion 38 of the vessel 28 througha tube 8|. The liquid 58 is subject to the temperature of the airambient the refrigbient temperature.

shell 52 of the refrigerator to which the receptacle 59 is secured actsas a heat conducting fln for the receptacle 59 to maintain thetemperature of the same in close relationship with the amy The liquid 28in the vessel 29 in this modification may comprise methyl chloride, andtheliquid 58, a solution of sodium chloride in which the methyl chlorideis insoluble or nearly so. As shown in Figs. 8- and 9 the liquid 58 isarranged to lie below the volatile fluid 28 because the former isheavier than the latter.

- It will be aparent from the above ,that this v 2,803,182 in theprevious modifications. The outer metal invention'provides a control fora mechanical refrigerator which compensates for room temperature and isresponsive to both the temperature of the evaporator and to that of theroom in which the refrigerator is operated. The control also providesfor the proper evaporator temperature for forming ice even at low roomtemperatures. I

While I have shown my invention in several forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications without departing from thespirit thereof, and I desire, therefore, that only such limitationsshall be placed thereupon as are specifically-set forth in the appendedclaims.

What I claim is:

1. In a mechanical refrigerator, the combination of an insulated cabinetcontaining a medium to be cooled, a cooling unit for eoolingthe mediummeans responsive to the ambient temperature of said cabinet'for movingthe liquid portion ofthe fluid in said vessel from onev of saidportions-of the vessel to another in a different heat exchangerelationship to vary the mean temperature of the cooling unit.

4. In a mechanical refrigerator,'the combination of an insulated cabinetcontaining a medium to be cooled, a cooling unit for cooling the mediumin said cabinet, apparatus for supplying refrigerant to the-coolingunit, a vessel having portions thereof in different degrees of heatexchange relationship with said cooling unit, a volatile fluidin saidvessel, said volatile fluid having portions in the liquid and in'thevapor phase, means responsive to the pressure of said vapor forcontrolling said refrigerant-supplying apparatus, and means responsiveto the ambient temperature of said cabinet for effecting the dispositionof liquid portions of said volatile fluid in at least some of saidvarious portions of said vessel to vary the mean temperature ofthe-cooling unit, the portion of said vessel in the most intimate heatexchange relationship with the cooling unit being of relatively largecapacity to maintain the temperature of the cooling unit in saidcabinet, apparatus for supplying refrigerant to said cooling-unit, avessel having portions thereof in difierent degrees of heat exchangerelationship with said cooling unit, a volatile fluid in said vessel,said volatile fluid having portions in the liquid and in the vaporphase, means responsive to the pressure of said vapor for controllingsaid refrigerant-supplying apparatus, and means responsive to theambient temperature of said cabinet for effecting the disposition ofvolabelow a predetermined limit.

5. In a,mechanical refrigerator, the combination of an insulatedcabinet, a cooling unit for said cabinet, apparatus for supplyingrefrigerant" to the cooling unit, and a vessel having a portion, thereofin intimate heat exchange relationship with the cooling unit anda'second portion thereof in heat exchange relationship with the coolingunit and with a medium warmer than said cooling unit to raise thetemperature of said second portion above that of the cooling unit, avolatile fluid in said-vessel, said fluid having portions in the liquidand in the vapor phase, means responsive to' the pressure'of said vaporfor controlling said refrigerant-supplying apparatus, and meansresponsive to an increase in the temperatureof the tile liquid in atleast some of said portions of the vessel to vary the mean temperatureof the cooling unit.

2. In a mechanical refrigerator, the combination of an insulated cabinetcontaining a medium to be cooled, a heat absorbing unit for cooling saidmedium, apparatus for supplying a heat absorbing material to said unit,a vessel having at least a part thereof lying in a'medium warmer thansaid heat absorbing unit, said part having-portions in different degreesof heat exchanging relationship with said heat absorbing unit to main.-tain said portions at difierent temperatures, a volatile fluid in atleast the coldest portions of said vessel, means responsive to the vaporpressure of said volatile fluid for controlling said apparatu's, andmeans responsive to the temperature ambient said cabinet for effectingcondensation of a portion of said vapor in the coldest available portionof said vessel as said temperature increasesto increase the vaporpressure of said volatile fluid.

3.-In a mechanical refrigerator, the combination of an insulated cabinetcontaining amedium to be cooled, a cooling unit for cooling the mediumin said cabinet, apparatus for suppl ing refrigerant to the coolingunit, a vessel having portions thereof in different degrees of heatexchange relationship with said cooling unit, a volatile fluid in saidvessel, said fluid having portions in the liquid and in the vapor phase,means reatmosphere ambient said cabinet for condensing quantities of thevapor -of said volatilefluid in said vessel to extend the liquid thereinto the second portion of said vessel to lower the mean temperature ofthe cooling unit.

v 6. In a mechanical refrigerator, the combination ofan insulatedcabinet, a cooling unit for said cabinet, apparatus for supplyingrefrigerant to the cooling unit, and a vessel having a portion thereofin heat exchange relationship with the cooling, unit and another portionthereof 'extending from the cooling unit into a zone of highertemperature, a chamber exterior of' said insulated cabinet, a movablepartition in said chamber dividing the same into two compartments,-

one of said compartments communicating with said-vessel, a volatileliquid in the portion of said vessel in heat exchange relationship withthe cooling unit and vapors of said liquid in the compartmentcommunicating with said vessel, means responsive to the vapor pressureof said liquid for controlling the refrigerant-supplying apparatus, anda second volatile liquid in the other compartment of said chamber, saidsecond volatile liquid being in heat exchange relationship 7 with theambient air of said cabinet, the vapor pressures of the first-named andthe secondnamed liquid being such that the differential between theirvapor pressures-moves said partition to decrease the volume of thecompartment communicating with the vessel when the temperature of theair ambient of said cabinet increases beyond predetermined limitsthereby condensing the vapors in said first-named compartment in theportion of said vessel extending away from the cooling unit.

'I. In a control mechanism for a mechanical refrigerator comprising aninsulated cabinet, a cooling unit therein, and refrigerant-supplyingapparatus exterior of said cabinet, the combination of a vessel having aportion thereof in heat exchange relationship with the cooling unit andanother portion thereof extending away from the cooling unit, a chamber,a movable partition therein dividing said chamber into two compartments,one of said compartments communicating with said vessel, a volatileliquid at least in the portion of said vessel in heat exchange with thecooling unit and vapors of said liquid in the compartment communicatingwith said vessel thus providing a liquid line in said vessel, a secondvolatile liquid in the other compartment of said chamber, said secondvolatile liquid being in heat exchange relationship with the ambient airof said cabinet, and means responsive to the vapor pressure of saidfirst-named liquid for controlling the refrigerant-supplying apparatus,the vapor pressure of the first-named and the second liquid being suchthat-the differential between their vapor pressures moves said partitionto decrease the volume of the compartment communicating with the vesselwhen the temperature of the air ambient of said cabinet increases,thereby condensing some of the vapor of the last-named compartment tosupply additional liquid in the vessel to bring the liquid line thereinfarther away from the evaporator into a warmer area 'of the insulatedchamber.

8. In a mechanical refrigerator, the combina- 4 tion of an insulatedcabinet containing a medium to be cooled, a cooling unit for cooling themedium in said cabinet, apparatus for supplying refrigerant to thecooling unit, a vessel having portions thereof in varying degrees ofheat exchange relationship with said cooling unit, a volatile fluid insaid vessel, said fluid having portions in the liquid and in the vaporphase, means responsive to the pressure of said vapor for controllingsaid refrigerant-supplying apparatus, a vapor-absorbing material locatedexterior of said cabinet and in communication with said vapor, thevapor-absorbing quality of said material varying inversely with itstemperature, said material absorbing some of said vapor when thematerial is at low temperatures and expellingsome of said vapor when athigh temperatures, said expelled vapor condensing in the coldestportions of said vessel available to said vapor to eflect a variation ofthe average temperature of the cooling unit.

9. In a mechanical refrigerator, the combination of an insulatedcabinet, a cooling unit for said cabinet providing a plurality ofrefrigerated zones of different temperatures thcrein, apparatus forsupplying refrigerant to the cooling unit, a vessel having portionsthereof in several of said zones, a volatile fluid insaid vessel, saidfluid having portions in the liquid and in the vapor phase, meansresponsive to the pressure of said vapor for controlling saidrefrigerant-supplying apparatus, and a second fluid located exterior ofsaid insulated cabinet communicating with a portion of said vessellocated in one of the colder zones, said fluid expanding with increasein tem- RAY HOND E. TOBEY.

